In a series of earlier patents, for example GB 1416734, GB 1533412 and GB 2021390, I disclosed mounting devices suitable for securing a post to a reinforcing channel on the rear of a sign panel, the channel mouth being furnished with inturned lips to retain elements of the mounting device. The mounting devices were typically pressed from stainless steel sheet, and the reinforcing channels were normally made from extruded aluminium. The system has proved extremely successful for many years; however I have now conceived of a modification or departure from that successful design concept which appears in practice to be surprisingly advantageous, particularly providing a construction of considerable strength and durability while economising substantially in the materials and costs involved.
Another aspect of the invention deals with the problem of forming larger signs from two or more panels abutted edge to edge. Conventionally some kind of construction or device is provided to prevent light from passing through a gap between adjacent panels, it being virtually impossible to provide a light-tight joint between the panels by simple abutment. Such devices or constructions which are used in practice tend to be expensive, complicated, unreliable or in other ways unsatisfactory. I have conceived of a construction which provides distinct advantages over some of the available alternatives. This aspect of the invention can employ the improved mounting device referred to in the preceding paragraph, to make use of the advantages provided thereby.